Cramping joint connector

Abstract: This invention relates to a cramping joint connector for connecting a branch coated wire with a main coated wire and connecting ends of coated wires. Slots (11) and (12) for accommodating coated wires (1) and (2) are formed in parallel relationship in an upper part of a housing body (10). The slot (11) is a through slot extending from one longitudinal end of the housing body (10) to the other longitudinal end thereof and adapted to accommodate an intermediate portion of the main coated wire (1). The other slot (12), one longitudinal end of which is open and the other longitudinal end of which is closed, is adapted to accommodate an end portion of the branch coated wire (2). At the closed end of the slot (12) is formed a holding hole (13) which extends continuously from the slot (12) toward the bottom of the housing body (10). A cramping contact terminal (15) is fitted transversely over the slots (11), (12). The branch coated wire (2) is bent after the end thereof in inserted into the holding hole (13), and fitted into the slot (12) along an extending direction thereof. When a cover member (24) is mounted on the housing body (10), the wires (1), (2) are pressed into the corresponding slots (11), (12), thereby being connected conductively to each other. With this arrangement, the wires (1), (2) are cramped at proper positions without displacement, allowing the cramping operation to be performed efficiently.

Description: This invention relates to a cramping joint connector for connecting a branch coated wire with a main coated wire and connecting ends of coated wires. The term coating includes electrically insulating material. As a cramping joint connector used to connect a branch coated wire with a main coated wire, there has been known the one as shown in Figs. 12 and 13. This connector is constructed such that flutes b, c are formed in side-by-side relationship in a housing a and a cramping contact terminal d having two legs is mounted insertably transversely of the axes of the flutes b, c on an upper face of the housing a. The flute b is adapted to accommodate a main coated wire 1 over its entire length. The flute c is provided with a wall defining an inner end thereof and adapted to accommodate an end portion of a branch coated wire 2. The main wire 1 is inserted into the flute b along a slit e which is formed in a side wall defining the flute b in a direction normal to the axial direction of the flute b. The end portion of the branch wire 2 is inserted into the flute c in the axial direction of the flute c. Thereafter, when the cramping contact terminal d is pressingly inserted with use of a pliers or like pinching instrument, the both legs of the cramping contact terminal d rip the coats of the wires 1, 2, and come into pressing contact with cores thereof, thereby permitting the wires 1, 2 to be conductive to each other. Finally, an upper part of the cramping contact terminal d is covered by a cover member f. However, the wires 1, 2 are liable to move axially in their positions accommodated in the flutes b, c in the conventional connector. Therefore, when the cramping contact terminal d is pressingly inserted, the wires 1, 2 may displace from their proper positions and may not be cramped at proper positions. Particularly, when the branch wire 2 displaces, it is cramped only slightly, which may cause the leg of the cramping contact terminal d to lose contact with the core of the wire 2 after the connection. In an extreme case, the wire 2 may come out of the flute c, thereby causing a connection error. The narrower the diameter of the wire relative to the diameter of the flute, the more marked these problems of the displacement. In order to avoid these problems, the cramping operation is carried out while holding the wires 1, 2 with finger tips. This operation has been in fact disadvantageous in terms of working efficiency because it is very difficult to hold the tiny wires properly and the wires tend to displace, thereby forcing the operator to try many times. From the DE-A-37 08 782 and the US-A-3,899,236 there are known cramping joint connectors having the features of the preamble of claim 1. It is an object of the invention to improve such a known cramping joint connector in order to better overcome the above stated problems. A further object of the invention is to provide a method of cramp connecting a first wire and a second wire allowing a fast, easy, and secure connection. The above objects are solved by a cramping joint connector having the features of claim 1 and by a method having the features of claim 9. Preferred embodiments are defined in the respective dependent subclaims. Due to the inventive holding means, the coated wires are prevented from being displaced in the slots during the cramping operation and can be cramped with one another at proper positions. Further, since it is not necessary to hold the wires with hand during the cramping operation, the operation can be carried out efficiently. At least one holding hole is formed in the housing so that an end portion of each coated wire may be inserted thereinto, the holding hole extending at an angle to and continuous with the corresponding slot. The angle is preferably 90 degrees, but may be smaller or greater than that as far as the coated wire must be bent toward the slot and fitted therein along its extending direction, after the end portion thereof is inserted into the holding hole. Hence, the coated wire is accommodated in the slot such that no displacement is possible. In a preferred embodiment, the slots comprise holding portions having a width slight smaller than the rest of the slots and the outer diameter of the wires. With this feature, the wires can be inserted into the slots where they are held without the coats thereof being ripped by the cramping contact terminal. It should be appreciated that the holding effect is, in general, not as good as that of the latter embodiment. An excellent holding effect is achieved by combining the holding hole and the holding portions of the slots. Preferably, the slot portions are upper longitudinal ends of the slot. Further, the inventive cramping joint connector preferably comprises the housing body including a plurality of slots and a cover member which is mounted to cover the housing body and presses the coated wires into the corresponding slots according to its mounted state. Preferably, a locking mechanism is provided on the housing body and the cover member for holding the cover member relative to the housing body in a first state where the cover member does not press the coated wires into the corresponding slots and in a second state where the cover member is completely mounted on the housing body with the coated wires being pressed into the slots. This arrangement acts as follows. The coated wire whose end portion is inserted into the holding hole can be held along the slot such that no displacement is possible, similarly to the foregoing arrangement. The cover member is mounted on the housing body halfway after the other coated wires are held along the corresponding slots. Subsequently, when the cover member is mounted on the housing body completely by pinching with use of a pinching instrument, the coated wires are accordingly pressed into the slots and the cramping contact terminal rips the coats of the coated wires and comes into contact with the cores thereof, thereby permitting the coated wires to be conductive to one another. Thus, similar to the foregoing arrangement, the displacement of the coated wires is prevented, thereby enabling the coated wires to be cramped securely at proper positions. It is not necessary to hold the coated wires with hand. Further, since the cover member is mounted on the housing body halfway by the locking mechanism, it is not necessary to hold the cover with hand, either. Accordingly, the cramping operation can be carried out more efficiently. The cramping contact terminal is adapted to be insertable into its position in the housing body. The terminal preferably includes cut-in portions, each comprising a slit into which the coated wire may be pressed. The slots include advantageously those extending from one side of the housing to the other side so as to accommodate therein intermediate parts of the coated wires and those for accommodating the end portions of the coated wires. The cramping joint connector including these slots is used to connect a branch coated wire with a main coated wire and enables the cramping operation to be performed accurately and efficiently for this type of connection. These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings in which: Fig. 1 is a perspective view showing a housing body of an embodiment of the invention in its unassembled state, Fig. 2 is a sectional view taken along a vertical plane in Fig. 1 where a through slot is formed in the housing body, Fig. 3A is a plan view in section showing the housing body, Fig. 3B is a sectional view taken along a vertical plane in Fig. 3A where a slot for accommodating an end portion of a branch coated wire is formed in the housing body, Fig. 4 is a perspective exploded view of the housing body and a cover member showing a mounting operation of the cover member, Fig. 5 is a vertical sectional view of Fig. 4, Fig. 6 is a perspective view showing a state where the cover member is mounted on the housing body halfway, Fig. 7 is a sectional view taken along a longitudinal vertical plane in Fig. 6, Fig. 8 is a sectional view taken along a transversal vertical plane in Fig. 6; Fig. 9 is a transversal vertical sectional view showing a state in which the cover member is mounted on the housing body completely; Fig. 10 is a perspective view, similar to Fig. 6, showing the state of Fig. 9; Fig. 11 is a longitudinal vertical sectional view showing the state of Fig. 9; Fig. 12 is a perspective view showing the prior art, and Fig. 13 is a plan view of Fig. 12. Hereafter, an embodiment of the invention will be described with reference to Figs. 1 to 11. A connector of this embodiment is used for connecting a branch coated wire 2 with a main coated wire 1. Indicated at 10 is a housing body made of synthetic resin. Slots 11 and 12 for accommodating the coated wires are formed in spaced-apart and parallel relationship in an upper part of the housing body 10. The slot 11 is a through slot extending from one longitudinal end of the housing body 10 to the other longitudinal end thereof and adapted to accommodate an intermediate portion of the main coated wire 1. The other slot 12, one longitudinal end of which is open and the other longitudinal end of which is closed, is adapted to accommodate an end portion of the branch coated wire 2. The depth of the slots 11, 12 is substantially equal to the height of a center portion of the housing body 10, and the width thereof corresponds essentially to the diameter of the coated wires 1, 2, wherein it is slightly smaller at upper longitudinal ends 11a, 12a of the slots 11, 12, so that the coated wires 1,2 are held when being fitted into the slots (Figs. 3A and 8). As shown in Figs. 3A and 3B, at the closed end of the slot 12 is formed a holding hole 13 into which the end portion of the branch wire 2 is inserted. The holding hole 13 extends toward a bottom face of the housing 10 and communicates with the slot 12. Between the slots 11, 12 is mounted a cramping contact terminal 15 made of conductive material. The cramping contact terminal 15 is such that two pairs of cut-in portions 16, each pair being spaced apart longitudinally in the direction of the slots, are connected through a connecting portion 18. A slit 17 is formed in each portion 16 extending transversely to the direction of the slots, so that a coated wire can be pressingly inserted into a pair of portions 16 while the coat thereof being ripped. The pairs of cut-in portions 16 are fitted into the corresponding slots 11, 12 while insertion portions 19 projecting downward from the bottom ends of the respective cut-in portions 16 are inserted and positioned into corresponding insertion holes 20 formed at the bottom faces of the slots 11, 12. As particularly shown in Figs. 3A and 3B, when the cramping contact terminal 15 is fixed at a predetermined position, the connecting portion 18 is in contact with an upper face 21a of a partition wall 21 between the slots 11 and 12 and holding portions 22 formed at outer side edges of the cut-in portions 16 are in contact with the outer sidewalls of the slots 11, 12. As shown in Figs. 4, 5, the housing body 10 is also provided with a cover member 24 made of synthetic resin, which is intended to cover the housing body 10. As shown in Fig. 5, a pressing portion 25 projecting downward is formed on an upper inner face of the cover member 24. The pressing portion 25 is intended to press the coated wires 1, 2 into the bottom parts of the slots 11, 12. A cut-off recess 26 is formed in the pressing portion 25 so that the pressing portion 26 may press the coated wires 1,2 without pressing the cramping contact terminal 15 and the like. According to Figs. 4 to 10, a window 28 is formed in each lateral side face of the cover member 24, and a first locking projection 29 and two second locking projections 30, the first locking projection 29 being located above the juxtaposed second locking projections 30, are formed in each lateral side face of the housing body 10. The first locking projections 29 are lockingly in contact with the lower edges of the windows 28 when the cover member 24 is mounted halfway, whereas the second locking projections 30 are lockingly in contact therewith when the cover member 24 is mounted completely. On each longitudinal side face of the housing body 10 is formed a guide rib 32 extending in a vertical direction along which the cover member 24 is guided and mounted. On each longitudinal side face of the cover member 24 is formed a guide groove 33 engageable with the corresponding guide rib 32. There will be next described an assembling procedure of the embodiment. With reference to Figs. 1 to 3, it is described how the coated wires are mounted in the housing body 10. An intermediate part of the main coated wire 1 is fitted into the slot 11 along an upper edge of the slot 11, thereby being held by the upper longitudinal ends 11a of the slot 11. The branch coated wire 2 is bent after the end thereof is inserted into the holding hole 13, and fitted into the slot 12 along an upper edge of the slot 12, thereby being also held by the upper longitudinal end 12a of the slot 12, as shown in Figs. 3A, 3B. Subsequently, as indicated by arrows in Figs. 4 and 5, the upper face of the housing body 10 is covered with the cover member 24, such that the guide ribs 32 engage with the corresponding guide grooves 33. The cover member 24 is pressed further downward while being guided by the guide ribs 32 and the guide grooves 33. Then, the lateral lower edges of the cover member 24 move over the first locking projections 29, which in turn come into locking engagement with the lower edges of the corresponding windows 28. In this way, the cover member 24 is mounted and locked on the housing body 10 halfway. In this state (Figs. 6 and 8), the pressing portion 25 of the cover member 24 is not pressing the coated wires 1, 2, into the slots 11, 12, but is located right above these wires 1, 2 as shown in Fig. 8. However, as shown in Fig. 7, the longitudinal lower edges of the cover member 24 press portions of the wire 1 projecting outward from the longitudinal side faces of the housing body 10, thereby holding the wire 1 in a bent state. One of the longitudinal lower edges of the cover member 24 also presses a portion of the branch coated wire 2 projecting outward from the corresponding longitudinal face of the housing body 10, thereby holding the wire 2 in a bent state. Since the end portion of the wire 2 is bent and inserted into the holding hole 13, this end portion will neither slip nor come out of position. Subsequently, the upper face of the cover member 24 and the lower face of the housing body 10 are pinched by, e.g., pliers so that the cover member 24 is mounted on the housing body 10 completely as shown in Figs. 9 to 11. This causes the cover member 24 to move toward the bottom of the housing body 10, and the lateral lower edges of the cover member 24 move over the second locking projections 30, which in turn come into locking engagement with the lower edges of the corresponding windows 28. During this movement of the cover member 24, the wires 1, 2 are pressed by the pressing portion 25 of the cover member 24 to be fitted into the corresponding slots 11, 12 and the cut-in portions 16 of the cramping contact terminal 15 rip the coats 3 of the wires 1, 2 and come into contact with the cores 4 of the wires 1, 2, thereby permitting the wires 1, 2 to be conductive to each other. According to the foregoing embodiment, when the cover member 24 is mounted and locked on the housing body 10 halfway with the cramping contact terminal 15 being inserted into the housing body 10, the main and branch coated wires 1, 2 are prevented from displacing and therefore can be cramped securely at a proper position during the cramping operation. Further, the cramping operation can be carried out efficiently since it is unnecessary to hold the wires 1, 2 and the cover member 24 with hand during this operation. Besides the one illustrated in this embodiment, there are other types of cramping joint connectors such as the one for connecting a plurality of branch wires with a main wire and the one for connecting only end portions of coated wires.

Claims: A cramping joint connector including a housing body (10) having a plurality of slots (11, 12) for accommodating a plurality of coated wires (1,2) and a cramping contact terminal (15) for ripping coats (3) of the respective coated wires (1, 2) when accommodated in the housing body (10) and for coming into contact with cores (4) of the respective coated wires (1,2), thereby permitting the coated wires (1,2) to be conductive to one another: comprising at least one holding means (13; 11a, 12a) formed in the housing (10, 24) for holding each coated wire (1; 2) at the housing body (10) before its coat being ripped, characterised in that said holding means comprise at least one holding hole (13) formed in the housing body (10) so that an end portion of a coated wire (2) may be inserted thereinto, the holding hole (13) extending perpendicular or tilted to and continuous with the corresponding slot (12). A cramping joint connector as defined in claim 1, wherein said holding means comprise holding portions (11a, 12a) of said slots (11, 12), said portions (11a, 12a) having a width slightly smaller than the rest of the slots (11, 12) and the outer diameter of the wires (1, 2). A cramping joint connector as defined in claim 2, wherein said slot portions are upper longitudinal ends (11a, 12a) of said slots (11, 12). A cramping joint connector as defined in any of claims 1 to 3, wherein said housing body (10) further includes: a cover member (24) which is mounted to cover the housing body (10) and, in its completely mounted state, is pressing the coated wires (1, 2) into the corresponding slots (11, 12). A cramping joint connector as defined in claim 4, further comprising: a locking mechanism (28, 29, 30) provided on the housing body (10) and the cover member (24) for holding the cover member (24) relative to the housing body (10) firstly in an intermediate state where the cover member (24) does not press the coated wires into the corresponding slots (11, 12) and finally in the completely mounted state. A cramping joint connector according to claim 4 or 5, wherein the cramping contact terminal (15) is insertable in the housing body (10). A cramping joint connector as defined in any of claims 1 to 6, wherein the terminal (15) includes cut-in portions (16), each comprising a slit (17) into which the coated wires (1,2) may be pressed. A cramping joint connector according to one or more of claims 1 to 7 wherein the slots (11,12) include those (11) extending from one side of the housing body (10) to the other side so as to accommodate therein an intermediate part of a coated wires and those for accommodating an end portion of a coated wire. A method of cramp connecting a first wire (2) and a second wire (1) comprising inserting an end portion of said first wire (2) into a retaining hole (13) formed in a housing (10, 24), bending said first wire (2) to place an adjacent portion thereof in a first slot (12) formed in the housing (10, 24), which first slot (12) is perpendicular or tilted with respect to said hole (13), placing said second wire (1) in a second slot (11) formed in the housing (10, 24), forcing and holding said first wire (2) and said second wire (1) against a cramping contact terminal (15) formed in the housing (10, 24) whereby said contact (15) penetrates insulation (3) on said first wire (2) and said second wire (1) to establish an electrical cramp connection therebetween. The method of claim 9 wherein said first wire (2) and said second wire (1) are first retained adjacent upper edges of said first slot (12) and said second slot (11) and then forced therein and against said contact (15).

Inventors: ITO OSAMU, ITO, OSAMU, ITO, OSAMU, C/O SUMITOMO WIRING SYSTEMS, LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01R4
IPC codes: H01R9, H01R4